1. Field of the Invention
The present invention relates to an electrical connector, more particularly to a connector inserted into a connector receiving recess fitted with a flexible print-circuit having a plurality of terminal connecting short strips. The connector also has a plurality of terminals each formed with an elastic contact piece for contracting one of the terminal connecting short strips through an opening of a terminal accommodating chamber of the connector.
2. Prior Art
A typical one of such connectors is shown in FIG. 8, which is known generally.
FIG. 8 shows a connector 1 having a rectangular connector housing 2 provided with a plurality of terminal accommodating chambers 3 (only one chamber is illustrated in FIG. 8) each of which receives a terminal 5 having an elastic contact piece 4. The connector is inserted in a connector receiving recess 7 fitted with a flexible print-circuit (called as FPC hereinafter) 6.
The plurality of terminal accommodating chambers 3 each have an opening 8 defined in a wall thereof to be opposed to FPC 6 of the connector receiving recess 7. The elastic contact piece 4 is constructed to project by a given distance from the opening 8. In addition, the plurality of terminal accommodating chambers 3 each have the opening at the rear end thereof for inserting a terminal 5 into the terminal accommodating chamber 3.
The terminal 5 is made of an electrical conductive metal and has both an elastic contact piece 4 and a wire connection portion 11 that crimps an electrical wire 10. The elastic contact piece 4 has a contact portion 12 in the middle of a folded-back forward part thereof. The elastic contact piece 4 is projecting from the opening 8 toward the wire connection portion 11.
The connector receiving recess 7 is defined in an instrument case 13 so as to receive the connector housing 2. FPC 6 arranged in the connector receiving recess 7 has a plurality of terminal connecting short strips (not shown) each connecting with the contact portion 12 of one of the terminals 5.
When the connector receiving recess 7 receives the connector 1, each elastic contact piece 4 deflects resiliently and abuts against the terminal connecting short strip (not shown) for electrical contact thereof with a suitable contact force.
Now, an object of the invention will be discussed hereinafter.
In the aforementioned prior art, as shown in FIG. 8, there may be variations in distance A between the opposite walls of the connector receiving recess 7, in distance B between FPC 6 and the second wall, and in an original height C from a bottom wall of the connector housing 2 to the contact portion 12. Thus, a deflection allowance D of the elastic contact piece 4 is not defined reliably, causing disadvantageously an unreliable contact force between the elastic contact piece 4 and the terminal connecting short strip.
In addition, since the instrument case 13, of which the connector receiving recess 7 and the connector housing 2 are made of synthetic resin, is influenced by a surrounding high temperature, the distances A, B of the connector receiving recess 7 vary in a larger range so that the elastic contact piece 4 may have an undesirable smaller contact force.
Meanwhile, the elastic contact piece 4 is limited in width, thickness, and deflection since it must be located in the terminal accommodating chamber 3 in relation to the connector receiving recess 7. Moreover, the elastic contact piece 4 is limited in material due to electric conductivity.
Furthermore, when the elastic contact piece 4 has a comparatively large elastic coefficient, the contact force varies in a lager range corresponding to the deflection of the elastic contact piece 4. Thus, a small variation of the dimensions A, C may cause a comparatively large variation of the contact force of the elastic contact piece 4, which may make the elastic contact piece 4 yield with time. Accordingly, as mentioned above, the elastic contact piece 4 provides an unsteady contact force against the terminal connecting short strip.